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Computational Intelligence for Analysing the Mechanical Properties of AA 2219 - (B4C + h-BN) Hybrid Nano Composites Processed by Ultrasound Assisted Casting

Radha P., Selvakumar N., Harichandran R.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 3

1163--1173

EN

The computational intelligence tool has major contribution to analyse the properties of materials without much experimentation. The B4 C particles are used to improve the quality of the strength of materials. With respect to the percentage of these particles used in the micro and nano, composites may fix the mechanical properties. The different combinations of input parameters determine the characteristics of raw materials. The load, content of B4 C particles with 0%, 2%, 4%, 6%, 8% and 10% will determine the wear behaviour like CoF, wear rate etc. The properties of materials like stress, strain, % of elongation and impact energy are studied. The temperature based CoF and wear rate is analysed. The temperature may vary between 30°C, 100°C and 200°C. In addition, the CoF and wear rate of materials are predicted with respect to load, weight % of B4 C and nano hexagonal boron nitride %. The intelligent tools like Neural Networks (BPNN, RBNN, FL and Decision tree) are applied to analyse these characteristics of micro/nano composites with the inclusion of B4 C particles and nano hBN % without physically conducting the experiments in the Lab. The material properties will be classified with respect to the range of input parameters using the computational model.

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Microstructure, surface topography and sliding wear behaviour of titanium based coating on AISI 1040 steel by magnetron sputtering

Selvakumar N., Malkiya R. P. R.

Archives of Civil and Mechanical Engineering

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2017

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Vol. 17, no. 2

281--292

EN

In the present study, 2% B4C reinforced with Ti–6Al–4V composite coatings on AISI 1040 steel plates were coated using magnetron sputtering. The microstructure and surface morphologies of the coated specimen were analyzed using SEM, XRD, EDS and AFM. The uniform coating thickness of 75 nm and 110 nm on smooth surfaces have been obtained for 0.5 h and 1 h coating time respectively. Under the normal load of 2 N and 3 N, Ti–Al–V–B4C coatings wear analysis were performed and resulted in excellent wear rate with lower coefficient of friction. Ti–Al–V–B4C thin film shows the nano hardness value of 7.2 GPa and 9.7 GPa for 0.5 h and 1 h coating time and elastic modulus of 204 GPa. The surface roughness (Ra) of 0.5 h and 1 h coating are 3.393 nm and 17.433 nm respectively. The addition of B4C particles reinforced Ti–Al–V composite coatings showed enhanced nano hardness and improved the wear resistance with decrease in the coefficient of friction. The amount of heat generated during wear test has been calculated. Ti–Al–V–B4C composite coatings were exposed to lowest wear rates among all loading conditions and thus signifying that it could be a promising alternative to other hard coatings.

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Effect of milled B4C nanoparticles on tribological analysis, microstructure and mechanical properties of Cu–4Cr matrix produced by hot extrusion

Singh S. C. E., Selvakumar N.

Archives of Civil and Mechanical Engineering

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2017

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Vol. 17, no. 2

446--456

EN

In this paper, the dry sliding wear and friction behavior of Cu-4Cr-xB4C nanocomposites produced by powder metallurgy by varying the proportions of boron carbide viz. (x = 0, 4 and 8 wt.%) were studied. Die set assembly was preferred for making green compacts using a compression testing machine. The sintered compacts were hot extruded at 600 °C to reduce the porosity and to attain preform density of 92%, thereby improving the hardness and wear resistance. Scanning electron microscope (SEM) and X-ray diffraction were used to characterize the powders. Vickers hardness tester was used to evaluate the hardness of different compositions. Pin-on-disc instrument was used to find out the wear behavior of the composites. It was found that the wear loss and friction coefficient increased with an increase in applied load and sliding distance for all the compositions. The wear mechanisms which could be interpreted with SEM analysis of the nanocomposites were also studied.

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Synthesis and characterization of NiO-ZnO nanocomposite by a cost efficient self-combustion technique

Vimal Kumar M., Gokul Raja T. S., Selvakumar N., Jeyasubramanaian K.

Journal of Achievements in Materials and Manufacturing Engineering

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2016

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Vol. 79, nr 1

13--18

EN

Purpose: In this research work the nickel oxide incorporated zinc oxide nano composite with various level of percentage such as (0.2, 0.4 and 0.6) were synthesized using combustion processes. Fuel used for the combustion process is hexamine in this work. Oxidizing agents taken were the nitrates of zinc and nickel. These precursor nitrates were heated with hexamine fuel to undergo combustion process. Design/methodology/approach: After combustion the particles were collected and heat treated to maintain the purity of the samples. XRD results were in well accordance with the JCPDS data and the average crystalline sizes were in the range of 10~20 nm. UV-VIS absorbance results confirm the band gap in the visible region. With increase in concentration of NiO in the composite red shifted from 320 nm to 374 nm. FTIR supports the presence of Zn-O and Ni-O bonds by the characteristic vibrational peaks at 432 cm-1 and 470 cm-1 respectively. PL spectrum studies results in the redshift of ZnO peaks from 380 nm to 400 nm with addition of Ni2+ ions inside the lattice. SEM and AFM studies reveals the morphological and topographical visualizations of the nanocomposite powders. Findings: In this research work, the authors had successfully synthesized Nickel substituted Zinc oxide by following simple combustion method followed by annealing. XRD analysis clearly evidences the formation of ZnO in the hexagonal wurtzite structure with an average crystallite size of 15 nm to 18 nm. An increase in Nickel peaks in between the Zinc oxide peaks were observed with increase in the nickel concentration in the composition. Practical implications: We conclude that combustion technique is suitable to fabricate Nickel incorporated Zinc oxide particles with high purity. This powder can be used in transparent conducting thin flims for OLED applications.

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Effect of h-BN solid nano lubricant on the dry sliding wear behaviour of Al-B4C nanocomposites

Harichandran R., Selvakumar N.

Archives of Materials Science and Engineering

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2016

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Vol. 77, nr 1

5--11

EN

Purpose: In this paper, three composites with different B4C content and fixed h-BN nanoparticles reinforced aluminium composites were fabricated through ultrasonic cavitation assisted casting. The role of the B4C and h-BN nanoparticles content on the mechanical and tribological properties of the aluminium composites was evaluated. This study presents the report on characterizion and evaluation of mechanical properties of h-BN and B4C nanoparticles reinforced aluminium composites. Design/methodology/approach: Al-B4C-h-BN composites are fabricated using stir and ultrasonic cavitation-assisted casting processes. The prepared composites are characterized using X-ray diffraction, Scanning Electron Microscopy and Energy Dispersive Spectroscopy. The dry sliding wear behaviour of the Al-B4C-h-BN composites are investigated using pin-on-disc wear test. Findings: The results of microstructural study reveal that uniform distribution, grain refinement and low porosity in composite specimens. The wear properties of the hybrid nanocomposites, containing 4 wt% B4C and 2 wt. % h-BN, exhibit the superior wear resistance properties as compared to unreinforced aluminium matrix. Practical implications: The interest in use of hexagonal boron nitride nanoparticles (h-BN) as solid nano lubricant for aluminium has been growing considerably due to its self lubricating properties.

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Influence of nano ZrC content on tribological analysis, microstructure and mechanical properties of Cu–4Cr matrix composites produced by hot extrusion

Selvakumar N., Singh S. C. E.

Archives of Civil and Mechanical Engineering

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2016

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Vol. 16, no. 3

537--552

EN

In the present study, Cu–4Cr–xZrC nanocomposites have been developed through powder metallurgy route by varying the proportions of zirconium carbide viz. (0–10 wt.%). The required green compacts were prepared using die set assembly in a compression testing machine. Consequently, the hot extruded samples were tested for dry sliding wear and friction using a pin-on-disc machine. SEM, XRD, pin on-disc system and Vickers hardness tester were used to evaluate the characterization, tribological properties and hardness respectively of Cu–4Cr–xZrC nanocomposites. From the observations, it was found that the friction coefficient increased progressively with increasing load and sliding distance. Furthermore, the specific wear rate (SWR) decreased for the Cu–4Cr–xZrC nanocomposites when compared to composites that of pure copper. Hardness increases with the addition of nano ZrC content into the matrix composites.

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Effect of nano/micro B4C particles on the mechanical properties of aluminium metal matrix composites fabricated by ultrasonic cavitation-assisted solidification process

Harichandran R., Selvakumar N.

Archives of Civil and Mechanical Engineering

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2016

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Vol. 16, no. 1

147--158

EN

Lightweight aluminium metal matrix nanocomposites play a major role in automobile, aerospace and other industries. This work aimed to investigate the effect of the addition of micro- and nano-boron carbide particles to aluminium on the mechanical properties of the composites. The micro- and nanocomposites containing different weight % of B4C particles were fabricated using stir- and ultrasonic cavitation-assisted casting processes. The fabricated micro and nano B4C particle-reinforced composites were characterized using scanning electron microscopy (SEM) and an X-ray diffractometer. Tensile, hardness, impact and wear tests were carried out in order to evaluate the mechanical properties of the micro- and nanocomposites. The tensile test results showed that the properties of the samples containing up to 6% nano B4C-reinforced composites were better than the micro B4C-reinforced composites. The study also indicated that the ductility and impact energy of the nanocomposites were better than the micro B4C particle-reinforced composites. The wear resistance of the nanocomposite significantly increased when the B4C content was increased up to 8% of addition, and this increase was more pronounced than that resulting from micro B4C particle-reinforced composites.